Comparison of rice husk- and dairy manure-derived biochars for simultaneously removing heavy metals from aqueous solutions: role of mineral components in biochars.
Comparison of rice husk- and dairy manure-derived biochars for simultaneously removing heavy metals from aqueous solutions: role of mineral components in biochars.
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DOI：
10.1016/j.chemosphere.2013.03.009
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发表时间：
2013-08
期刊：
影响因子：
8.8
通讯作者：
Xiaoyun Xu;Xinde Cao;Ling Zhao
中科院分区：
文献类型：
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作者：
Xiaoyun Xu;Xinde Cao;Ling Zhao
以稻壳生物炭和牛粪生物炭为吸附剂，对水溶液中的Pb、Cu、Zn、Cd进行了吸附研究。DMBC比RHBC更有效地去除所有四种重金属，每种金属的去除能力均超过486 mmol kg− 1，远高于RHBC（65.5-140 mmol kg− 1）。当4种金属共存时，RHBC表现出比DMBC更强的金属去除竞争，Pb的影响最小，Cd的抑制最大。在多金属体系中，当每种金属为1 mM时，RHBC的金属去除率降低了38.4- 100%，远高于DMBC的2-40.9%。RHBC对金属去除的较强竞争是由于所有金属仅竞争离子化的酚-O-基团，而DMBC对金属的去除不仅来自与离子化的羟基-O-基团的络合，还来自金属与富含DMBC的CO 3 2-和/或PO 4 3-的沉淀，导致竞争较小。通过XRD、FTIR、SEM等仪器分析以及Visual MINTEQ化学模拟，证明了两种生物炭去除金属的不同机理。结果表明，废弃生物质可转化为高附加值的生物炭，作为重金属吸附剂，其去除能力因生物炭原料来源不同而异，其中来源于原料的CO 32-、PO 43-等矿物组分对生物炭的吸附性能起着重要作用.
Rice husk biochar (RHBC) and dairy manure biochar (DMBC) were prepared as sorbents for simultaneously removing Pb, Cu, Zn, and Cd from aqueous solutions. DMBC was more effective in removing all the four heavy metals than RHBC, with the removal capacities of above 486 mmol kg− 1 for each metal, much higher than those of RHBC (65.5–140 mmol kg− 1). RHBC showed stronger competition for metal removal than DMBC when the four metals coexisted, with Pb the least affected and Cd the most inhibited. When each metal was 1 mM in the multi-metal system, the metal removal by RHBC was reduced by 38.4–100%, much higher than that reduced by 2–40.9% for DMBC. The stronger competition for metals removal by RHBC was due to the fact that all metals competed only for the ionized phenolic-O− groups, while the removal of metals by DMBC resulted not only from the complexation with ionized hydroxyl-O− groups but also from the precipitation of metals with CO 3 2-and/or PO 4 3-that were rich in DMBC, resulting in less competition. The different mechanisms for the removal of metals by the two biochars were evidenced by the instrumental analysis of XRD, FTIR, and SEM as well as chemical modeling of Visual MINTEQ. Results indicated the waste biomass can be converted into value-added biochar as sorbents for removal of heavy metals and the removal ability varies with different biochar feedstock sources where the mineral components such as CO 3 2-, PO 4 3-originated from the feedstock play an important role in the sorption nature of biochar.